In the conventional art, an HMD is known in which focus adjustment is allowed. For example, an HMD of monocular type is known that presents an image to user's one eye. The HMD includes an adjuster for focus adjustment. The adjuster has a ring shape and is rotatable about an axis serving as a pivot and extending in the same direction as the longitudinal direction (referred to as the “right and left directions”, hereinafter) of the housing. A part of the adjuster is exposed to the outside through a slit provided in the housing. The optical axial distance between a liquid crystal display holder and a lens holder in the housing varies in accordance with rotation of the adjuster. The user performs operation of applying a force on the portion exposed from the slit within the adjuster, in the up and down directions perpendicular to the right and left directions by using a finger and thereby rotates the adjuster. By virtue of this, the user changes the optical axial distance between the liquid crystal display holder and the lens holder and thereby performs focus adjustment.